Gas fired ribbon burner and electrode assembly



Jan. 20, 1970 TEMPLE 3,490,856

GAS FIRED RIBBON BURNER AND ELECTRODE ASSEMBLY Filed March 14, 1968YINVENTOR. HERAM E. TEMPLE United States Patent 3,490,856 GAS FIREDRIBBON BURNER AND ELECTRODE ASSEMBLY Hiram E. Temple, Rosemead, Califi,assignor to Baker Perkins Inc., Saginaw, Mich., a corporation of NewYork 1 Filed Mar. 14, 1968, Ser. No. 713,071 Int. Cl. /23, 3/00; F23115/26 US. Cl. 431122 7 Claims ABSTRACT OF THE DISCLOSURE .A ribbon burnerand electrode assembly wherein an elongate tubular burner havinglongitudinally extending burner ports is ignited by an electrodesupported by an insulating housing extending coextensively with theburner, the electrode being mounted for rotational movement from apredeterminable position in which the charge transmitting end of theelectrode is spaced from the burner ports to a position in which it isadjacent the burner ports and scrapes graphite and like deposits off theports, and wherein spring mechanism biases the electrode to re turn tooriginal position so that when released the electrode will ignite thefuel gas issuing from the ports as it returns to original position andcreates a gap across which an igniting spark Will jump.

It is conventional practice to use a graphite lubrication of the typewherein graphite is dispersed in kerosene to maintain chains travelingwithin bakery ovens and the like adequately lubricated. Difficulty hasbeen encountered in electrically lighting fuel gas burners in such ovensbecause graphite tends to collect or deposit on the burner ports.Another problem which has been encountered in such ovens is that ofmaintaining the proper gap between the electrode edge and the burnerports to provide opti mum performance. Even though the gap is properlyset in the first place, ignition difficulties have been encountered,following the replacement of electrodes which have been removed forcleaning and replaced by bakery personnel.

One of the prime objects of the present invention is to provide a burnerassembly having a disassemblable electrode member which is so designedthat proper positioning of the electrode edge relative to the burnerports is rendered automatic upon initial installation or replacementfollowing cleaning, and the danger of the flag being mispositioned sothat raw gas does not ignite and is emitted to create a dangerousexplosive condition in the oven is eliminated.

A further object of the invention is to design a burner and electrodeassembly which does not require use of a peep-hole to adjust theposition of the electrode, and which cannot slip out of preadjustedposition.

Another object of the invention is to design a burner and electrodeassembly which is operable to remove graphite and other shortingdeposits from the burner ports.

Still another object of the invention is to provide a ribbon burnerelectrode assembly which is positive in operation and wherein themanipulative parts which are used to effectuate ignition are locatedoutside the oven and can be conveniently operated.

Still another object of the invention is to provide a very eflicient andhighly reliable ribbon burner and electrode assembly of relativelysimple construction which can be very economically manufactured andassembled for sale to the baking industry for use in the baking ovens ofcommercial bakeries.

Other objects of the invention will become apparent from theaccompanying description and appended claims.

3,490,856 Patented Jan. 20, 1970 In the drawings:

FIGURE 1 is a fragmentary, sectional, top plan view, taken through anoven side wall and illustrating the novel oven burner and electrodeassembly which is provided for electrically igniting fuel gas whichissues from the side ports of the burner.

FIGURE 2 is a fragmentary, front elevational view thereof.

FIGURE 3 is an enlarged, fragmentary view of certain electrode operatingparts, taken on the line 33 of FIGURE 2.

FIGURE 4 is a fragmentary, front elevational view thereof.

FIGURE 5 is an enlarged fragmentary view showing the electrode flagswung over to engage the burner port grill members.

In my United States Patent No. 3,352,346, entitled Ribbon BurnerElectrode Assembly. issued Nov. 14, 1967, I disclose a burner andelectrode assembly which does an excellent job of locating the chargetransmitting end of an electrode flag relative to the burner ports. Thisassembly, however, does not have the capability of removing depositsfrom the burner ports, and in some installations this latter capabilityis of extreme importance.

Referring now more particularly to the accompanying drawings in whichonly a preferred embodiment of the invention is illustrated, a letter Wgenerally indicates the insulated side Wall of an enclosed baking ovenof conventional design which includes top and bottom walls as well asside walls, and is of the type used in the baking of bread and otherbakery products. A fuel gas burner assembly generally designated B issupported in position on the side wall of the oven and includes atubular casing member 10 projecting longitudinally into the oven usuallytransversely of the length thereof. A typical installation showing atunnel oven of considerable length, in which a large number of suchburner and electrode assemblies are used in transverse disposition, isdisclosed in United States Patent No. 2,801,686.

The burner B which is shown may be considered to be of exactly theconstruction disclosed in my United States Patent No. 3,172,460, andaccordingly the burner B will not be described in detail. As disclosedin that patent, the burner casing or barrel 10 is closed at its innerend by an end wall 11 (FIGURE 5) and a longitudinally extending slot 12is provided in one of its sides for ac commodating the port formingribbon or grill assembly generally designated R which is made up ofelectrically conductive metal strips of the character disclosed in bothof my aforementioned patents forming burner ports p. At its outer end,adjacent the side wall W, the burner casing 10 is coupled by sleeve 13to a housing section 14 which is fixed Within a burner box 15 extendingthrough an opening 16 in the wall W. A cover plate 17 for the box 15 maybe secured to the wall W by cap screws 18. A premixed hydrocarbon gasand air mixture under a predetermined pressure is supplied to the burner10 which preferably includes a manifold assembly 19 of the characterdisclosed in my United States Patent No. 3,172,460, via a supply pipe 20extending from any suitable conventional fuel gas source.

Extending coextensively with the burner assembly B is a removablecontiguous igniter unit, generally identified by the letter I, whichincludes a casing or housing 21 extending through an opening 22 providedin the wall 17 of burner box'15. As in my aforementioned Patent No.

' 3,353,346, an axially projecting electrode rod 23 is fixed understoodthat rod 23 extends back through the casing 21 in the manner indicatedin United States Patent No. 3,352,346 to connect with a charge supplyingwire carrying sheath 25 in the usual manner.

At its front end the casing 21 is supported for rotation by a yoke Y,open at its outer end to permit removal of the casing 21, which issecured to the burner casing 10. At its rear end a crank arm handle orlever generally designated 26 is secured to the casing 21. The crank armor actuator lever 26 is provided with a clamp ring 26a and may besecurely clamped to the reduced rear end 21a of the electrode casing 21by suitable means such as a capscrew 26b. A spring assembly generallydesignated 27 is provided for maintaining the arm 26 and accordingly theflag 24, in the position shown in FIGURE 2 wherein the flag is spacedfrom the burner ports p. As FIGURES 3 and 4 indicate, the springassembly 27 includes an angle member 28, adjustably secured to theburner box front plate 17 by means such as a bolt 29 extending throughan elongated slot 30. A bolt member 31, extending freely through anopening 260 in the arm 26, has a threaded end received in a threadedopening 32 provided in the angle support member 28 to function as aspring guide for a coil spring 33 which is interposed between thesupport 28 and a Washer 34 on bolt member 31.

Provided in the same manner, as in my aforementioned Patent No.3,172,460, above the igniter electrode I, is the peep-hole cover 35,which is mounted on an arm 37 to swing outwardly and upwardly about apin 36. The cover 35 covers an opening in plate 17 which, when the cover35 is swung upwardly, permits the workman to see into the interior ofthe oven. As previously indicated, it will be necessary from time totime to remove the electrode assembly I in the manner indicated in myPatent No. 3,352,346 for cleaning and to replace it, and the peep-holewill permit the workman to do this without physically entering the oven.

To remove the electrode assembly the cap screw 29 is first removed. Itis then merely necessary to grasp the end 26a of the casing 21 and swingthe casing 21 outwardly laterally from the burner B and out of the yoke26. When the casing 21 is then moved rearwardly, the assembly I can betilted to pass the flag 24 out the opening 22. Reinsertion of theelectrode assembly I is also a simple matter and can be accomplished byinserting the flag 24 in tilted position through opening 22 and thenreplacing the casing 21 in the yoke 26. After this, the ca p screw 31can be replaced. It is desirable to maintain a gap of about .020 of aninch between the flag edge 24a and the ribbon burner assembly. Becauseof the unique construction of the present burner and electrode assembly,it is not necessary to maintain the gap by estimating whether or not itis proper when looking through the peep-hole into the interior of theoven. Instead, the handle 26 can be pressed upwardly in the clockwisedirection of the arrow a in FIGURE 2 until the flag 24 engages theribbon burner elements R, and the bolt 31 can then be tightened down tomaintain it in this position. The bolt 31 can then be backed off therequired predetermined number of revolutions which will automaticallyprovide the proper gap between the edge 24a and the ribbon burnerelements R for optimum sparking.

In the operation of the device the burner is lighted by the operatorgrasping the protruding end of the angle 28 and the arm 26 between thethumb and forefinger of one hand, for instance, and pressing the handle26 toward the protruding end of the angle support 28 to compress spring33. The fiag 24 will be moved in a clockwise direction to the positionin which it is shown in FIGURE 5, and in so doing will scrape graphitedeposits from the ribbon burner element R. With the electrical power on,when arm 26 is released and is sharply returned by the spring 33 tooriginal position, a spark jumps the gap and ignition is achievedvirtually every time at the instant gas begins to issue from the burnerribbon assembly R, thus avoiding the creation of the dangerous explosiveatmosphere which might otherwise result. If, for some reason, thegraphite deposit should not be completely removed, to the extent thatthe electrical short is removed, the lever 26 can, of course, be jiggledto fully dislodge the graphite and break the short so that ignition canoccur.

It is to be understood that various changes may be made in theconstruction shown and described to effectuate the same or similarresults without departing from the spirit of the invention or the scopeof the appended claims. The foregoing descriptive matter and drawingsare intended only as illustrative, and the invention is defined by theclaims.

I claim:

1. A burner assembly comprising: an elongate tubular burner havinglongitudnaly extending burner port means; means for supplying fuel gasto said tubular burner and burner port means; electrode rod support andinsulating means extending generally coextensively with said burner andhaving an electrode with a charge transmitting end; means mounting saidelectrode rod for movement from a position in which said electrodecharge transmitting end is spaced from said burner port means through apath of movement in which it wipes said burner port means; and means forsupplying an electric charge to said electrode to ignite fuel gasissuing from said port means.

2. The combination defined in claim 1 wherein spring means biases saidelectrode rod to the position wherein the electrode end is spaced fromthe burner port means.

3. The combination defined in claim 1 in which said electrode rodsupport and insulating means extends through an oven wall and has a rearend extending outside said wall; a crank handle fixed on said rear end;and adjustable spring means biasing said handle to an adjustable rotaryposition in which said electrode end is spaced from said burner portmeans.

4. A burner assembly comprising: an elongate tubular burner havinglongitudinally extending burner port means; means for supplying fuel gasto said tubular burner and burner port means; electrode rod support andinsulating means extending generally coextensively with said burner andhaving an electrode with a charge transmitting end; means mounting saidelectrode rod for rotational movement from a position in which saidelectrode charge transmitting end is removed from said burner port meansto a position in which it is adjacent said burner port means and meansfor supplying an electric charge to said electrode rod to ignite fuelgas issuing from said port means; said electrode end wiping across saidburner port means and scraping carbon deposits therefrom in moving tosaid adjacent position.

5. A burner and oven wall assembly comprising: an elongate tubularburner having longitudinally extending burner port means; means forsupplying fuel gas to said tubular burner and burner port means;electrode rod support and insulating means extending generallycoextensively with said burner and having an electrode with a chargetransmitting end; means mounting said electrode for rotational movementfrom a positon in which said electrode charge transmitting end isremoved from said 'burner port means to a position in which it isadjacent said burner port means; means for supplying an electric chargeto said electrode rod to ignite fuel gas issuing from said port means;said electrode rod support and insulating means extending through saidoven wall and having a rear end extending outside said wall; a crankhandle fixed on said rear end; and spring means biasing said handle tothe rotary position in which said electrode end is removed from saidburner port means.

6. A burner assembly comprising: an elongate tubular burner havinglongitudinally extending burner port means; means for supplying fuel gasto said tubular burner and burner port means; electrode rod support andinsulating means extending generally coextensively with said burner andhaving an electrode with a charge transmitting end; means mounting saidelectrode rod for rotational movement from a position in which saidelectrode charge transmitting end is removed from said burner port meansto a position in which it is adjacent said burner port means; means forsupplying an electric charge to said electrode rod to ignite fuel gasissuing from said port means; and actuator means for rotating saidelectrode rod including an actuating arm secured to said electrode rod,a bracket spaced from said arm, and a biasing element mounted betweensaid arm and said bracket.

7. The combination defined in claim 5 in which a support is mounted infixed position at a spaced distance from 2/1916 Owen 431-256 3/1965Temple et a1 431180 EDWARD G. FAVORS, Primary Examiner US. Cl. X.R.239114; 431-264

